While live bacteria commonly cause infection, the relative rile of bacterial toxins and the live bacteria to produce morbidity and mortality is not know, If bacterial toxins are important factors, therapies directed at these toxins may be required even if no live bacteria to remain alive and grow may also be important in determining morbidity and mortality and continued antibiotics may be important therapy. Using two E. coli in the canine model, we designed a study in the summer of 1988 to determine whether organism virulence factors or bacterial toxins were more important in producing septic shock. Measures of hemodynamic shock, blood cultures, endotoxin levels and survival were done serially with both organisms live, both organisms killed, and with purified endotoxin from these organisms. Approximately 4 man years have gone into this study. Preliminary results from this study have been presented at the American Federation of Clinical Research and the Society of Critical Care Medicine. This presentation won a poster award in 1990. There has been much interest in these data as determination of the factors that produce morbidity in infection will guide trials for future therapies of children and adults with septic shock.